Maybe not the most accurate name, since this does nothing on its own relative to the cap on pounce damage.

CVarsz_pounce_damage_range_min - The minimum distance for a pounce to be given more than 1 damage.z_pounce_damage_range_max - The distance at which a pounce is worth its maximum (1+z_hunter_max_pounce_bonus_damage)

Basically, this means that pounce damage scales linearly with z_pounce_damage_range_min/max as endpoints (min: 1 damage, max 1+z_hunter_max_pounce_bonus_damage).
However, in L4D2, there is no CVar control of the min_dist and max_dist. This plugin adds those two cvars.

The default values for these cvars are as follows:z_pounce_damage_range_min: 300.0 (500 in l4d1)z_pounce_damage_range_max: 1000.0 (same in l4d1)

So, if I pounce someone from 650 units away, I'll do 1 + (24 * 350 / 700) = 13 damage.
If I want to double the pounce damage limit, but keep the same scaling on l4d2, I'd set: